Peculiar bursts of energy called chorus waves have been detected in deep space far from our planet, suggesting they could pose problems for long-distance space travel. 

The discovery of chorus waves happened by accident—and not in space but on Earth—when World War I radio operators overheard them emanating from thunderstorms. “People were listening for enemy transmissions, and they instead heard this chorus of ‘birds,’” says Allison Jaynes, a space weather physicist at the University of Iowa, who was not involved with the study. “It turned out later they were listening to chorus waves produced by lightning.”